Jetstar first officer James Fuller was forced to pull up his Airbus A320 when he spotted the critter, believed to be an eastern snake-neck turtle, enjoying a sunbaking session on the side of the tarmac on Thursday.

The plane had been taxiing towards its take-off point when Mr Fuller and Captain Nigel Waccura realised the lump they'd spotted off the right wing was actually alive.

They quickly pulled up and applied the park brake before informing passengers that the lazy reptile was holding up their travel plans.

"We radioed the tower and apparently it was the second time he'd been up there that day," Mr Fuller told AAP on Friday.

"He was about a foot long. With the cooler weather he was enjoying a sunbake out there on the tarmac. So we just put the park brake on.

"The captain made an address to the passengers just letting them know why we'd stopped. I think a few of them were up trying to take photos out the window."

A safety car was sent out to relocate the turtle to a nearby creek, and pilots are now keeping a keen eye out in case he returns.

Mr Fuller says he and Mr Waccura shared a chuckle as they waited for the all clear.

"The engine inlet was pretty close, so there is the potential for things to be sucked in," he said.

"We had a bit of a giggle amongst ourselves. I've seen rabbits and foxes and things around the airport, but obviously they move a lot faster."

Jetstar passenger Lachlan Burnet said the unusual flight delay made his day.

"(They) brought the plane to a stop for a few minutes ... to allow a gorgeous little turtle to cross the taxiway in front of the aircraft and make his way (yes, slowly - give him a break ... it's a turtle!) to the creek near the airport fence," he posted on Twitter.

"Lovely stuff ... well played."

Australian Associated Press